DNS outbound: Keep hijacked A/AAAA replies within the buffer (#7225)

https://github.com/XTLS/Xray-core/pull/7225#pullrequestreview-5613859264

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Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: 风扇滑翔翼 <Fangliding.fshxy@outlook.com>

proxy/dns/dns.go

@@ -381,6 +381,13 @@ func (h *Handler) handleIPQuery(id uint16, qType dnsmessage.Type, domain string,
 		errors.LogInfoInner(context.Background(), err, "pack message")
 		b.Release()
 		timer.SetTimeout(0)
+		return
+	}
+	if len(msgBytes) > buf.Size {
+		b.Release()
+		timer.SetTimeout(0)
+		errors.LogError(context.Background(), "DNS response message too large")
+		return
 	}
 	b.Resize(0, int32(len(msgBytes)))